On 2014/01/27 17:56:56, kexec <kexec-bounces at lists.infradead.org> wrote:
> On 01/27/14 at 01:03pm, HATAYAMA Daisuke wrote:
> > (2014/01/23 18:47), Baoquan He wrote:
> >
> > > @@ -3301,18 +3301,15 @@ set_bitmap(struct dump_bitmap *bitmap, unsigned long long pfn,
> > > }
> > >
> > > int
> > > -set_bitmap_cyclic(char *bitmap, unsigned long long pfn, int val)
> > > +set_bitmap_cyclic(char *bitmap, unsigned long long pfn, int val, struct cycle *cycle)
> > > {
> > > int byte, bit;
> > >
> > > - if (pfn < info->cyclic_start_pfn || info->cyclic_end_pfn <= pfn)
> > > - return FALSE;
> > > -
> >
> > Removing this check changes behaviour, not just clean up, so should be separated into another patch.
> >
> > Further, this change seems buggy because, in addition to Kumaga-san's comment, memory outside of
> > cycle region can be passed to here. Please look at the below.
>
> Hi Both,
>
> I understand your finding. How about put the pfn checking back to
> set_bitmap_cyclic(). Maybe this is simpler and safer. Otherwise each
> case need be taken care and adding the pfn checking.
Agreed, and this simple check may have a small influence on the
performance, so I think it's OK to do it.
Thanks
Atsushi Kumagai
>
> >
> > > @@ -4782,10 +4780,10 @@ exclude_unnecessary_pages_cyclic(void)
> > > if (mmd->mem_map == NOT_MEMMAP_ADDR)
> > > continue;
> > >
> > > - if (mmd->pfn_end >= info->cyclic_start_pfn &&
> > > - mmd->pfn_start <= info->cyclic_end_pfn) {
> > > + if (mmd->pfn_end >= cycle->start_pfn &&
> > > + mmd->pfn_start <= cycle->end_pfn) {
> > > if (!__exclude_unnecessary_pages(mmd->mem_map,
> > > - mmd->pfn_start, mmd->pfn_end))
> > > + mmd->pfn_start, mmd->pfn_end, cycle))
> > > return FALSE;
> > > }
> > > }
> >
> > After this clean up, __exclude_unnecessary_pages() processes memory within cycle region only.
> > So, it's necessary to pass adjusted range, like:
> >
> > if (MAX(mmd->pfn_start, cycle->start_pfn) < MIN(mmd->pfn_end, cycle->end_pfn))
> > __exclude_unnecessary_pages(mmd->mem_map, MAX(mmd->pfn_start, cycle->start_pfn), MIN(mmd->pfn_end, cycle->end_pfn))
> >
> > --
> > Thanks.
> > HATAYAMA, Daisuke
> >
> >
> > _______________________________________________
> > kexec mailing list
> > kexec at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/kexec
>
> _______________________________________________
> kexec mailing list
> kexec at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/kexec
>
